Hot Water Heater Pre-Heating Apparatus

ABSTRACT

Disclosed is a hot water heater supplement and means of utilizing waste heat from a refrigeration cycle. The apparatus comprises a refrigerator having a compressible refrigerant, a compressor, a condenser, a refrigerant receiver tank, an expansion valve and an evaporator for changing the temperature, pressure and phase of the refrigerant in a standard refrigeration cycle. The condenser is a coaxial, water cooled heat exchanger that receives waste heat from the high temperature, condensing refrigerant. The heated water is pumped into a coaxial heat exchanger within a heat exchange tank, which heats a volume of water within the exchange tank that is then mixed with a hot water heater tank for use in a residence. Cold water is fed into the exchange tank and thus pre-heated before being moved to the hot water heater, which utilizes either a gas or resistance style heating means.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No. 61/511,346 filed on Jul. 25, 2011, entitled “Hydro Fridge.” The patent application identified above is incorporated here by reference in its entirety to provide continuity of disclosure.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to hot water heaters, refrigeration cycles and capturing waste heat from a refrigeration cycle for preheating a hot water heater. More specifically, the present invention pertains to a closed-loop, dual coaxial heat exchanger that receives heat from a refrigerator condenser and heats household water in an exchange tank for preheating water entering a hot water heater.

Refrigerators are common household appliances that utilize a phase-change operation of a compressible medium to create a chilled environment within the appliance interior for food storage. These devices utilize a refrigeration cycle that is well known in the art, which involves the compression of refrigerant, condensing the refrigerant by removing heat from the refrigerant to change its phase from a vapor to a liquid before an expansion valve and evaporator change its phase once again to a liquid, drawing heat from an environment adapted to be cooled. This closed-circuit cycle allows the refrigerant phase change to remove heat from a low temperature region and reject heat to a high temperature region, wherein the refrigerant is recycled and contained within the cycle. The process of rejecting or removing heat in the process occurs when the refrigerant passes through the condenser, wherein waste heat is removed from the process and into the environment. This heat is generally expelled into the environment and constitutes a waste or unrealized use of heat from the cycle.

The waste heat from this cycle can be capitalized upon and utilized in a secondary process rather than being wasted in the environment. The heat can be utilized for mechanical work or further in a heating process of another medium. The present invention pertains to such a waste heat recapturing apparatus, wherein the latent heat from an air-cooled condenser is replaced with a liquid-cooled, coaxial heat exchanger for drawing heat from the refrigerant and into a liquid medium. This heated medium is then pumped into an exchange tank for preheating a volume of water, which is then fed into a larger hot water heater. Pre-heating the water entering the hot water heater reduces the overall burden on the heater and its demands to raise the temperature of the water from a lower temperature to one that is comfortable for use in a residential or commercial establishment. The required energy from the resistive or gas-powered hot water heater is therefore reduced, as the heat from the refrigerator is utilized as a means to supplement the hot water heater using a cycling, dual-coaxial heat exchanger and a preheated exchange tank prior to feeding the hot water heater.

2. Description of the Prior Art

Devices have been disclosed in the prior art that relate to refrigeration cycle waste heat repurposing apparatuses. These include devices that have been patented and published in patent application publications, and generally relate to improved efficiently cycles that utilize the waste heat rather than releasing it into the atmosphere. The forgoing is a list of devices deemed most relevant to the present disclosure, which are herein described for the purposes of highlighting and differentiating the unique aspects of the present invention, and further highlighting the drawbacks existing in the prior art.

Specifically, U.S. Pat. No. 4,373,345 to Tyree discloses an ice-making and water heating device that utilizes recovered heat from an ice maker, comprising liquid refrigerant from a high pressure received is expanded and supplied to an evaporator. Expanded refrigerant returns to a compressor through an accumulator and the high pressure vapor is condensed by a heat-exchanger with circulating water withdrawn from a storage tank. The water is heated as the refrigerant vapor gives off heat through the condenser, whereafter the heat may be utilized as pre-heated water in another process or for a different function.

Another device is U.S. Pat. No. 4,487,032 to Speicher, which discloses a device for utilizing waste heat from a household refrigerator and utilizing it with a hot water heater, wherein water is heated by a condenser of the refrigerator and further by an oil cooling loop from the refrigerator compressor, together which heat the water for reuse in a hot water tank. The twice-heated water can be stored in a hot water tank and distributed throughout a home for hot water use. The Speicher device utilizes the waste heat from a refrigerator and the heat generated by the refrigerator compressor to heat water prior to being mixed directly within a hot water heater. The present invention utilizes a closed-loop, dual heat exchanger that preheats water prior to being moved into a hot water heater and mixed therein.

U.S. Pat. No. 4,293,093 to Raymond discloses another device for exchanging heat energy between a refrigeration circuit and a hot water system, wherein the device heats water in a combination refrigerant desuperheater water preheater and then conducted to hot water storage. A fitting mixes the preheater with water in a hot water tank prior to discharging that water into a hot water system. While utilizing a preheater prior to mixing water with a hot water heater, the Raymond device utilizes a desuperheater water preheater rather than a closed-loop, circulating liquid heat exchanger that transfers heat from the condenser to a preheating heat exchange tank.

Further, U.S. Pat. No. 4,246,764 to Papadakos discloses a water and energy conserving apparatus that supplies pre-heated water to a hot water heater and for cooling at least one refrigeration unit. The apparatus comprises a pre-heater tank adapted to be connected to a cold water supply. A heat exchanger accepts heated compressible medium from the refrigeration cycle heats up the cold water by removing heat from the compressible medium, after which the heated water is pumped directly into a pre-heater tank. While similar in intent, the present invention utilizes a dual heat exchanger that draws heat from the refrigerator condenser and then exchanges heat with cold water from an exchange tank, whereafter the preheated water from the exchange tank is placed within a hot water heater for further heating through an electrical resistance or fuel burning process.

Finally, U.S. Pat. No. 5,220,807 to Bourne discloses a combined refrigerator-water heating system, comprising an insulated food storage compartment and an insulated water storage compartment. A refrigeration cycle that includes compressible refrigerant is utilized to cool the food compartment, while a condenser is utilized to heat the water storage compartment. A resistance heating element within the water storage compartment is also utilized on combination with the condenser, wherein the heater utilizes a logic and time-of-day signal to bias the electrical heating to time of off-peak electrical use and thus reduce energy consumption and cost for heating water. The Bourne device relates to an improved system that utilizes logic to conserve energy or utilize energy during nonpeak and low cost times, saving the homeowner money and improving overall efficiency of the system.

The present invention pertains to a heat exchange device that preheats water entering a hot water tank using a circulating, dual-coaxial heat exchanger device that utilizes waste heat from a refrigeration cycle as a means to preheating household water. It is submitted that the present invention substantially diverges in design elements from the prior art, and consequently it is clear that there is a need in the art for an improvement to existing hot water preheating devices. In this regard the instant invention substantially fulfills these needs.

SUMMARY OF THE INVENTION

In view of the foregoing disadvantages inherent in the known types of hot water preheating devices now present in the prior art, the present invention provides a new preheating device utilizing waste heat from a refrigeration cycle and a preheating exchange tank, wherein the same can be utilized for providing convenience for the user when improving overall efficiency of a refrigerator and hot water heater while reducing energy costs for the homeowner.

It is therefore an object of the present invention to provide a new and improved hot water preheating device that has all of the advantages of the prior art and none of the disadvantages.

It is another object of the present invention to provide a hot water preheating device that utilizes waste heat expelled from a refrigeration cycle and utilize it as a means of preheating water prior to a hot water tank.

Another object of the present invention is to provide a hot water preheating device that replaces a condenser with a liquid-liquid heat exchanger for drawing heat from a refrigeration cycle and condensing the refrigerant in the process.

Yet another object of the present invention is to provide a hot water preheating device that utilizes a single or dual coaxial heat exchanger to transfer heat from a refrigerator compressible refrigerant medium to cold water in a preheating exchange tank.

Other objects, features and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTIONS OF THE DRAWINGS

Although the characteristic features of this invention will be particularly pointed out in the claims, the invention itself and manner in which it may be made and used may be better understood after a review of the following description, taken in connection with the accompanying drawings wherein like numeral annotations are provided throughout.

FIG. 1 shows a pictorial view of the present apparatus.

FIG. 2 shows a schematic view of the present invention and its elements.

DETAILED DESCRIPTION OF THE INVENTION

Reference is made herein to the attached drawings. Like reference numerals are used throughout the drawings to depict like or similar elements of the hot water preheating device. For the purposes of presenting a brief and clear description of the present invention, the preferred embodiment will be discussed as used for preheating water entering a hot water heater via waste heat from a refrigeration cycle. The figures are intended for representative purposes only and should not be considered to be limiting in any respect.

Referring now to FIG. 1, there is shown a pictorial view of the present preheating and heat recapturing device of the present invention. The system comprises a refrigeration unit 11 that operates a standard refrigeration cycle, wherein compressible refrigerant or similar material is induced into several phase changes to absorb and release heat for the purpose of cooling the refrigerator interior. Another key component of the system is a household hot water heater 13, which normally intakes cold water and heats the water to a desired temperature through electrical resistance heating or a fuel burning process. Finally, a preheating water exchange tank 12 is provided as an intermediary between the cold water intake 19 and the hot water heater 13, wherein the cold water 19 is heated by an exchange process that elevates the incoming water prior to entry into the hot water heater. This reduces the burden on the hot water heater and thus energy expenditure for heating lower temperature water to that desirable for user showering, cleaning and for other household uses.

The means of heating the cold water 19 in the exchange tank 12 includes a heat exchange between the refrigerator 11 and the exchange tank 12, wherein otherwise wasted heat from the refrigerator condenser is utilized to heat a medium within a liquid-liquid heat exchanger 15 and pumped 18 into a second liquid-liquid heat exchanger 14 within the exchange tank 12. The first heat exchanger 15 reduces the temperature of the refrigerant for the purpose of condensing it from a vapor to a liquid or liquid and vapor mixture prior to being accumulated and returned to the refrigerator compressor for recirculation. Normally this heat is exhausted from the refrigerator by an elongated condenser coil that utilizes a liquid-air exchange process; however in the present invention a coaxial heat exchanger absorbs heat from the refrigerant in a similar process. The heated material within the exchanger 15 is then pumped 18 into a second heat exchanger 14 within the exchange tank 12 for heating cold water. Losses in the cycle limit the ability of the exchangers to raise the temperature of the cold water 19 to an acceptably high user temperature, as the ceiling for the exchanger is less than the temperature of the condensing refrigerant. Therefore, the water in the exchange tank 12 is considered a preheating exercise, wherein this preheated water 20 is then fed into the hot water heater 13 for further heating and distribution 21. The heated material from the second exchanger 14 is reduced in temperature and pumped back 16 to the first exchanger 15 for reheating by the condensing operation of the refrigerant.

Referring now to FIG. 2, there is shown a schematic view of the present preheating cycle. As shown, the three primary components of the system are the refrigerator 11 and its refrigeration cycle, the preheating exchange tank 12 and the hot water heater 13. The refrigeration cycle 11 includes a compressor 27 that compresses a refrigerant medium to a high pressure gaseous state, after which the refrigerant enters a liquid-liquid heat exchanger 15 that draws heat from the refrigerant and changes its phase from a vapor to a liquid or to a vapor and liquid mixture. The liquid refrigerant is then collected in a receiver tank 22 and forced through an optional refrigerant dryer if required. An expansion valve 24 is utilized to transform the high pressure liquid refrigerant into a low pressure refrigerant that is then run through an evaporator 25. The evaporator 25 changes the phase of the refrigerant back to a gaseous state by drawing heat from the surrounding environment before being accumulated 26 and recompressed. This phase change process is well described in the art of refrigeration cycles, and is utilized as a means of drawing heat from an interior refrigerator compartment and for distributing cold air therewithin.

During this process, however, heat is normally expelled from the refrigerant by the condenser as heat is drawn from the high pressure gas being transformed into a liquid state. In the present cycle, the condenser includes a first coaxial heat exchanger 15 utilizing an appropriate medium to absorb this heat, after which the medium is pumped 18 from the condenser through a conduit 17 to a second coaxial heat exchanger 14 for transferring the absorbed heat to cold water 19 within the exchange tank 12. Rather than expelling the heat from the condenser into the environment as waste heat, the heat exchanger 15 utilizes this energy as a means to preheat household cold water supplies 19 prior to the water being placed into the hot water heater 13 for further heating. The preheated water 20 thus requires less energy to elevate its temperature to a desired, usable level for household use. The hot water heater 13 may utilize an electrical resistance or fuel-burning means of heating the preheated water before being distributed 21 to the user in a shower, to the kitchen or to any other household appliance or outlet drawing hot water.

Conventional refrigerators expel large quantities of waste heat from their condenser coils, blowing the warm air into the living spaces of a home. This is a problem in both air conditioned households and commercial spaces, as the warm air emitted from freezers and refrigerators raises the ambient air temperature within the space and requires the climate control system to expel further energy to maintain a desired indoor temperature. As the atmospheric temperatures of living spaces and restaurant kitchens rise, consumers are forced to waste energy and further place an unnecessary strain on an air conditioning system in extreme heat environments. Another consideration is the heat expelled during a refrigeration cycle, which is generally squandered into the environment as a waste product. This heat includes inherent energy for work or for further heating auxiliary systems or other secondary systems. It is therefore submitted that the present invention discloses a means of capturing and repurposed which wasted heat for the purposes of preheating a hot water heater water supply. The system is designed to utilize an insulated water exchange tank in-line with the water heater and upstream, wherein the water heater accepts preheated water rather than cold or ambient water. The implementation of this system may serve to eliminate unnecessary emission of hot air from refrigerators, while also repurposing the heat to raise the temperature of water needed for cooking, washing clothes, showering, and other domestic or commercial purposes. The use of a dual heat exchanger, and specifically a coaxial heat exchanger, ensures efficient exchange of energy between the refrigerator heat and the exchange tank incoming water supply. The circulating fluid within the exchanger may be water or similar fluid material suitable for liquid-liquid heat exchangers.

It is therefore submitted that the instant invention has been shown and described in what is considered to be the most practical and preferred embodiments. It is recognized, however, that departures may be made within the scope of the invention and that obvious modifications will occur to a person skilled in the art. With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.

Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. 

I claim: 1) A hot water preheating system, comprising: a refrigerator having a refrigeration cycle that utilizes a compressible material and phase change operation, including a compressor, condenser, expansion valve and evaporator for cooling a refrigerator internal compartment; a hot water heater for heating incoming water to a desired level; a preheating exchange tank for accepting an incoming water supply, preheating a quantity of said water supply before sending said preheated water to said hot water heater for further heating; said refrigerator condenser further comprising a first heat exchanger element for drawing heat from said compressible material, wherein said material undergoes a transition from a vapor to a liquid phase; a conduit from said first heat exchanger connecting to a circulating pump, said pump circulating a heat exchange material from said first heat exchanger element and through a second heat exchanger element to a return pipe to said first exchanger; said second heat exchanger element being positioned in said preheating exchange tank for preheating incoming water. 2) The device of claim 1, wherein said first heat exchanger element further comprises a first coaxial heat exchanger. 3) The device of claim 1, wherein said second heat exchanger element further comprises a second coaxial heat exchanger. 